H91F0 - Riparian mixed forests of Quercus robur, Ulmus laevis and Ulmus minor, Fraxinus excelsior or Fraxinus angustifolia, along the great rivers (Ulmenion minoris)

General

Description habitat

This habitat type includes riparian mixed forests of Quercus robur, Ulmus laevis and Ulmus minor, Fraxinus excelsior or Fraxinus angustifolia, along the great rivers (Ulmenion minoris). The plant community belonging to this habitat type is the White poplar-Elm forest and, more specifically, the association Violo odoratae-Ulmetum of the Alno-Padion (sub class Ulmenion minoris) class.

Enironmental conditions.

This habitat type can be found on recent alluvial deposits. It develops on high sandy soils, which rarely flood. Elms develop if the groundwater level can subside to a minimum of 1-2 meter below ground level during the growing season. The White poplar-Elm forest functions optimally at a mean spring groundwater level of >60cm below ground level #4.

Control and growth opportunities

Forests can only develop if there is no or very extensive grazing. Literature mentions a maximum of 20-30 grazers or 30-50 grazers per 100ha #6 for softwood riparian forests.

Dose-effect relations

The main determining environmental factors for this habitat type are the inundation period, groundwater level, soil type and grazing density.

Flow chart

Dose-effect relations

days/year	HSI
0-5	1
5-20	1
20-35	0.5
> 35	0

Reference: #2, #5

days/year		HSI
0	0
0.4	0
0.6	1
1.5	1

Reference: #4,#5

Soil type	HSI
sand	1
clay	0
loam	0
peat	0

Reference: #3

Number of grazers per 100 ha	HSI
0-5	1
5-10	1
10-15	1
15-20	0.7
20-25	0.3
30-35	0

Reference: #6

Uncertainty and validation

These dose-effect relations have not been validated.

Applicability

These dose-effect relations are mainly formulated based on information from the Netherland. This habitat model can be applied to all large Dutch rivers.

Example project

The dose-effect relations of the inundation period have been used for the river area #2.

References

1 Janssen, J.A.M. en Schaminee, J.H.J. (2004). Europese natuur in Nederland; Habitat typen. KNNV Uitgeverij, Utrecht. ISBN: 9050111661
2 Klijn, F., S.A.M. van Rooij, M. Haasnoot, B.L.W.G. Higler & B.S.J. Nijhof. (2002) Ruimte voor de Rivier, Ruimte voor de Natuur. WL-rapport Q2824.10, Alterra-rapport 513. ISSN 1566-7197
3 http://www.minlnv.nl/natura2000
4 Runhaar, H. Waternood. Hydrologische randvoorwaarden voor natuur.
5 Duel, H. & B. Specken (1994). Standplaatsmodel Essen-Iepenbos: een model voor het bepalden van de standplaatskwaliteit van rivieroevers en uiterwaarden voor essen-iepenbossen (Fraxino-Ulmetum). TNO-BSA. RIZA werkdocument 96.046x
7 Westhoff, V. & A.J. den Held (1969). Plantengemeenschappen in Nederland. Zutphen.